surface epithelium 1

Histology 1

Surface epithelium

Dr. Arsalan Amiri

What do you see in the slide ?!Staining HE, PAS, …

Which organ Kidney,..

Which part Medulla,..

What kind of tissues Arteries, vein,…

Type of cuttingLongitudinal section, tangential cut, cross section

Staining methods1.Hematoxylin-Eosin

Hematoxylin - blue, basicacidic structures (basophilic):DNA, RNA, calcification, acidic proteoglycans, Nuclei, ribosomes.

Eosin - red, acidicbasic structures (acidophilic):Proteins, cytoplasm, ct. fibers, RBC

Suppressed staining (white)!carbohydrates, lipids

Staining methods2. AZANAzocarmine: red - nuclei, cytoplasm

Anilinblue: blue - ct. fibers

Staining methods3. periodic acid-Schiff (PAS)purple mucous (goblet cell), glycogen, microvilli, and reticular fibers (basal membrane).

Epithelial tissues

Surface epitheliumGlandular epitheliumSensory epitheliaOthers-Pigmented epithelium-Myoepithel-Epithelial-reticulum-Parenchymal organs

Surface epithelium

- covering external or internal surfaces- separate the tissues from the environment

Surface epithelium

-Squamous

- cuboidal

- columnar

Surface epithelium

Cell identification is based on shape of the nuclei

Surface epithelium

simple stratified Pseudostratified

Simple epithelia

Simple squamous- endothel (vessels)Compact (brain) – fenestrated (kidney)

- mesothel (serous membranes)pleura, pericardium, peritoneum-lung, kidney, rete testis-eye chamber, CSF space, inner ear

Simple epithelia

Simple cuboidalsmall ducts (glands, bile)Kidney (renal tubules) Ovary (surface)eye lens

Simple epithelia

Simple columnar epitheliaPlain (smooth)-bigger ductsMicrovilli (cuticula)-GI tractKinociliated-uterus, Fallopian tube

Simple epitheliaMicrovilli (cuticula)(0.1 x 2 µM)

actin microfilaments -> terminal web ->zonula adherensfunction: increases surface

Pseudostratified All cells are in contact with the basal lamina but not all of them reach the surface

plain-biggest ducts

Stereociliated-ductus epididymidis, d. deferens

Kinociliated-airways

Cutting of cell

Cutting of tissueA- Longitudinal sectionB- tangential cutC- cross section

Papilla of the kidney

• medulla of the kidney, from a pyramid

Papilla of the kidney HE• Longitudinal section of tubulesA. Square-shaped cuboidal cell lined tubuleB. Endothelium (vessels): flattened, extremely thin cytoplasm, flattened ovoid nuclei

bulging into the lumen

C. RBC (7-8 µm)D .Simple squamous epithelium (Henle's loop)

A

B D

Papilla of the kidney HE• Tubules in cross section A. Trapezoid shaped cuboidal cell lined tubuleB. Endothelium (vessels): many times the nuclei not vissible

C. RBC (7-8 µm)D .simple squamous epithelium (Henle's loop) E. Connective tissue

D A E B

Mesothelium AgNO3Squamous epithelium (derived from mesoderm)

lining body cavity epithelium is called mesothelium

covers the serous membranes (pleura, peritoneum and pericardium).

Serous membranes are shiny and slippery membranes that cover e.g. most guts from outside.

Mesothelium AgNO3The preparation is made from frog mesentery (no fat cells).

AgNO3 penetrated into the (20 nm) spaces in between the cells. Then it was exposed to UV light, so the Ag precipitated into the spaces, this draws the contour of the cells.

if you move the micrometer, you will see two layers of puzzle-like cell patterns of peritoneum (minimal connective tissue between them).

Mesothelium AgNO3Melanophoras (chromatophora) In some of the slides large, star shaped, dark cells with processesresponsible for changing the shade of color in certain animals. (pigmented connective tissue cells).

Jejunum

Mesothelium HE

Mesothelium HEJejunum• Smooth muscle :• A. cross section• B. longitudinal section• C. simple squamous epithelium, mesothelial cells (tunica serosa)

A

B C

Small intestine with villi (finger-like protrusions )

Intestinal villi HE


• Simple columnar epithelium with striated border (microvilli):• All cells of simple epithelia rest on lamina basalis.• egg shaped nuclei

Intestinal villi HE


The columnar cells are hexagonal prisms

Intestinal villi HE

Intestinal villi HESmall intestine with villi (finger-like protrusions )Simple columnar epithelium with striated border (microvilli):

Lymphocytes• small• very basophilic• round nuclei with a light ring around them.

• if the tissue was not fixed soon enough after death, microvilli may disappear.


Other structures seen in the slide:- loose connective tissue- Vessels- smooth muscle- endothelium in the central lacteal (seen as a widely opened space in the axis of

some villi)- mesothelium on the outer surface of the intestine.

Intestinal villi HE


tangential cut:

very thin (0.5 µm thick) slide of the same tissue:

Some nuclei appear to be smaller, because only a slice of them (around a smaller diameter) is in the actual picture.

Intestinal villi HE

Uterine tube Fe-H• Simple columnar epithelium with kinocilia

Axoneme : (central core of a Cilia)- 2 Central microtubule- 9 Outer doublet microtubule- Dynein arm (motor protein responsible for movement)

Uterine tube Fe-H• Simple columnar epithelium with kinocilia The slide was made from the oviduct.

Uterine tube Fe-H• Simple columnar epithelium with kinocilia• iron-haematoxyline: The tissue treated with Fe(III)-

ammonium sulphate before the H staining.

Uterine tube Fe-H• Simple columnar epithelium with kinocilia• staining the kinocilia and their anchoring basal

bodies (a dark line in the apical portion of the columnar cells).

• Basal bodies are moving center of the cell (cytoskeleton)

Uterine tube Fe-H• Simple columnar epithelium with kinocilia

• The height of the epithelium may vary from low columnar (close to cuboidal shape) to higher columnar depending on the hormonal status.

Uterine tube Fe-HSimple columnar epithelium with kinocilia• Sometimes taller secretory cells with elongated nucleus

and without kinocilia wedge in-between the columnar cells, these are the peg cells.

Other tissues in the slide:• loose c. t. • smooth muscle• vessels.

epididymis HEPseudostratified columnar epithelium with

stereociliaCells height varies. The nuclei are mostly oval, perpendicular to the

surface with their longitudinal axisthe nucleus of each reserve cell (close to the basal

lamina) is smaller and round.


stereociliaThe epididymis contains two types of ducts:

• the ductuli efferentes testis (these drain the product of the testis)

• the ductus epididymidis (an extemely tortuous single tube).

epididymis HEPseudostratified columnar epithelium with stereocilia

The ductus epididymidis - sections are larger in diameter- their epithelium is regular- the inner contour of the lumen even

The ductuli efferentes testis- smaller- the height of the epithelium varies- irregular inner contour


stereociliaThe ductus epididymidis:

The stereocilia:Long processes from the apex hang into the lumen They are huge microvilli and have a resorptive function



Other structures seen in the slide: loose c.t. smooth muscle cells ductuli efferentes testis

sometimes testis.

epididymis AZANPseudostratified columnar epithelium with


Other structures seen in the slide: loose c.t. smooth muscle cells ductuli efferentes testis

sometimes testis.

Epiglottis PAS-HPseudostratified columnar epithelium with

kinocilia- typical epithelium of the respiratory tract- cells are tall and narrow (the nuclei partially cover each other)


kinocilia The reserve cells with round nuclei seem to form a row

at the base. Between these cells there are narrow gaps through which the elongated columnar cells are in contact with the basement membrane


kinociliaIn the epithelium we see: - goblet cells (purple spots in the epithelium) - Lymphocytes (small, dark-blue, round nucleus with a

pale ring around it).

If the epithelium was infected segmented neutrophils may be present.


kinocilia The respiratory tract has a thick basal membrane. at the border of the epithelium and connective tissue(thick, homogenous, cell free stripe, pink with eosin and purple with PAS staining).


kinocilia

At the bottom of the slide a small portion of the elastic cartilage of the epiglottis is seen, with the purple cytoplasm of the

cartilage cells

Trachea, HEPseudostratified columnar epithelium with

kinociliaThe row of basal bodies The kinocilia. The goblet cells (pale oval spots)

Trachea PAS-HPseudostratified columnar epithelium with

kinocilia- 0.5 micrometer thick section- fewer nuclei overlap and the structure seems to

be more "simple".

Thank you for your attention

surface epithelium 1

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